Gillingham suffered their fifth straight league defeat on Saturday as Port Vale sealed a late 2-1 victory at Vale Park.
Chris Whelpdale gave the Gills a deserved lead on the stroke of half-time, but Sean Rigg levelled matters and a late Marc Richards penalty gave Vale all three points.
Manager Andy Hessenthaler walked straight over to the referee at the full time whistle to voice his frustration after seeing his side concede twice in the last 10 minutes - disputing a decision not to send off Vale's Gareth Owen and believing the ball went out of play in the build-up to Vale's winner.
Having lost their previous five games it was imperative that the Gills stopped the rot quickly to keep up the pressure on rival sides with play-off aspirations - including Vale themselves.
In order to accomplish that the manager made five changes to the side that lost to Southend on Monday evening, with four of those coming in defence as he plumped for a completely new back line.
Jack Evans and Connor Essam made their full league debuts after coming on as second-half substitutes last week, Simon King returned in the centre to partner Essam with Danny Jackman slotting in at left-back, with Whelpdale and Jack Payne brought into midfield.
New signing Ollie Lee had to make do with a place on the bench.
Vale made just the one change. Rob Taylor replacing Adam Yates in defence.
Both sides looked eager to make the best possible start, and after Vale had threatened early on the visitors slowly got a hold on the game.
Gavin Tomlin in particular looked lively and the midfield battles looked interesting from the outset as Payne and Whelpdale looked to command proceedings in the first 10 minutes.
The first chance however fell to the hosts as Doug Loft's 25-yard strike with his left foot went inches over the bar with Paulo Gazzaniga struggling to back pedal.
Sam Morsy's free kick just a minute or so later failed to test the Argentine as his effort went high and wide to the relief of the Gills fans behind the goal.
Chris Whelpdale should have perhaps opened the scoring in the 15th minute. Vale struggled to clear their lines after Curtis Weston's initial strike at the back post, and the returning midfielder failed to hit the target from just inside the box.
With 28 minutes on the clock Stuart Tomlinson was called into action for the first time as Jackman's long-range effort was well gathered at the second attempt.
Whelpdale's effort from a similar distance a few minutes later was saved in identical fashion.
Five minutes before the break and this time it was Tomlin's turn to have a crack at goal. He twisted and turned inside the box to lose his marker but his eventual left-foot effort was rather tame and the striker pulled it across the keeper and out for a goal kick.
But seconds before the half time whistle was due Whelpdale headed the Gills in front.
Tomlin collected the ball on the right-hand side and curled an inviting ball towards the back post, and the midfielder was on hand to give the visitors a deserved lead after finding a gap in the defence.
It was his fifth goal of the season and was perfectly timed as the referee soon brought the half to a close.
The Gills were good value for their interval lead, having played some impressive football in the opening period.
Vale looked for an immediate response after the break, but the Gills failed to be intimidated and were intent on claiming a second goal to ease the nerves.
Loft forced a save from Gazzaniga on 53 minutes which saw the hosts win a corner, and the keeper was on hand again to punch clear from the resulting set-piece.
Micky Adams made a triple substitution just before the hour mark to try and mix things up, but the Gills defence were equal to every task.
The back four were put under immense pressure on 65 minutes as Vale won successive set pieces, but the visitors dug in and ensured their advantage was maintained.
Danny Kedwell - skippering the Gills for the first time - could have done better with his effort a couple of minutes later, but he struck straight at the keeper from 20 yards.
At the other end Gazzaniga had to parry a shot from outside the box, before Essam threw his body on the line to prevent an almost certain equaliser.
Louis Dodds then delivered a great cross into the box which Richards met, but Vale's top scorer was unable to divert goalwards and the visitors weathered the storm for a few more minutes at least.
From the resulting goal kick Kedwell soon found himself clear through on goal, and with just Tomlinson to beat he seemed to have too much time and ended up striking straight into the keeper's arms.
With just over 10 minutes to go Vale should have been reduced to 10 men. Tomlin outmuscled Owen was through on goal, only to be pulled back right on the edge of the area. The assistant referee flagged, and referee Darren Drysdale awarded a free-kick.
However, despite Owen being the last man, Drysdale failed to produce even a yellow card and the hosts escaped what perhaps should have been an almost certain sending off.
The free-kick was wasted and seconds later the home side were level, Loft swinging over a fine cross from the right which Rigg met at the far post and headed past Gazzaniga.
This launched the Gills back into life - Tomlin working his way beyond a defender inside the box and unleashing a powerful effort.
However with the angle against the striker the ball only met the chest of the advancing goalkeeper as the ball left the danger zone.
There was more controversy a minute from time, when Loft was adjudged to have kept the ball in, and his cross towards Richards saw Vale's captain pushed to the ground by Whelpdale - and Drysdale had no hesitation to pointing at the spot.
Richards picked himself up and sent Gazzaniga the wrong way to give Vale a lead which had looked so unlikely for most of the afternoon.
The Gills tried to force a late equaliser but their efforts came to nothing and they trudged off having lost their fifth straight league game - although their performance was much improved on the previous four.
Vale: Tomlinson, Taylor, Griffith, McCombe, Loft, Dodds, Richards, Rigg, Morsy (Marshall 59), Williamson (Shuker 59), McDonald (Owen 59).
Unusued subs: Martin, James.
Gills: Gazzaniga, Evans, Essam, King, Jackman, Whelpdale, Payne, Weston, Tomlin, Kedwell, Kuffour (Martin 77).
Unusued subs: Richards,Montrose, Miller, O Lee.
Booked: King (45), Jackman (64)
Goals: Whelpdale (45), Rigg (81), Richards (89).
Referee: D Drysdale
Attendance: 4,027 (188 Gills)